mnn-engines

MNN engine libraries — arm64-v8a

The eight MNN runtime libraries used by the Pashbox Books Android app (native/modules/mnn-vision-bridge). Published publicly so the app and its build tooling can fetch them without an access token.

These are the MNN inference engine only. No model weights are here — the trained OCR models are kept in a separate private repository.

Files

Provenance

libMNN.so carries the build paths of the upstream alibaba/MNN GitHub Actions CI (/home/runner/work/MNN/MNN/build_64/...), and bundles Arm's KleidiAI 1.14.0 microkernels. A string scan of all eight libraries found no credentials, no personal paths and no internal hostnames.

Dependencies and load order

Read from each library's DT_NEEDED entries — this is the real dependency graph, not a listing order:

libMNN.so                                   -> libc++_shared.so
libMNN_Express.so  libMNN_CL.so
libMNN_Vulkan.so   libmnncore.so            -> libMNN.so
libMNNAudio.so     libMNNOpenCV.so          -> libMNN_Express.so, libMNN.so
libllm.so          -> libMNN_Vulkan.so, libMNN_CL.so, libMNNOpenCV.so,
                      libMNNAudio.so, libMNN_Express.so, libMNN.so

A valid load order is therefore: libMNN → libMNN_Express, libMNN_CL, libMNN_Vulkan, libmnncore → libMNNAudio, libMNNOpenCV → libllm.

Two things are not in this repo:

• libc++_shared.so — every library here needs it. It is the Android NDK C++ runtime and ships inside the APK; it is not redistributed here.
• libmnn_bridge.so — the app's JNI bridge. It is built from mnn_bridge.cpp by CMake during the Android build and is never downloadable.

Recommended use: bundle at build time

Place the eight files in modules/mnn-vision-bridge/android/src/main/jniLibs/arm64-v8a/ before building. The APK then ships them and MnnVisionBridgeModule loads them at startup, where the dynamic linker resolves every DT_NEEDED dependency from the app's native library directory.

Loading them at runtime with System.load() from an arbitrary app-data path is not equivalent: that path is not on the linker's search path, so dependencies are resolved from elsewhere or not at all, and libc++_shared.so is not here to be downloaded.

Licence

MNN is licensed under the Apache License 2.0 — see LICENSE, copied verbatim from alibaba/MNN. KleidiAI is likewise Apache-2.0, © Arm Limited. This repository redistributes those binaries; it is not affiliated with or endorsed by Alibaba or Arm.